Re: lazy_scan_heap() forgets to mark buffer dirty when setting all frozen?

On 2019-Apr-07, Andres Freund wrote:

> lazy_scan_heap() contains the following block:
>
> /*
> * If the all-visible page is turned out to be all-frozen but not
> * marked, we should so mark it. Note that all_frozen is only valid
> * if all_visible is true, so we must check both.
> */
> else if (all_visible_according_to_vm && all_visible && all_frozen &&
> !VM_ALL_FROZEN(onerel, blkno, &vmbuffer))
> {
> /*
> * We can pass InvalidTransactionId as the cutoff XID here,
> * because setting the all-frozen bit doesn't cause recovery
> * conflicts.
> */
> visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
> vmbuffer, InvalidTransactionId,
> VISIBILITYMAP_ALL_FROZEN);
> }
>
> but I'm afraid that's not quite enough.

Apparently the initial commit a892234f830e had MarkBufferDirty, but it
was removed one week later by 77a1d1e79892.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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